It is known that nano concave-convex structure bodies having a nano concave-convex structure body on the surface develops an antireflection performance by the continuous change of the refraction index. Also, the nano concave-convex structure body can develop a super water-repellent performance by Lotus effect.
As an example of the method for forming a nano concave-convex structure, proposed are, for example, a method which contains injection molding or press molding using a stamper having an inversion structure of a nano concave-convex structure, a method which contains providing an activation energy ray-curable resin composition (hereinafter, referred to as resin composition”) between a stamper and a substrate, curing the resin composition by irradiation of an activation energy ray to transfer the concave-convex structure of the stamper, and thereafter detaching the stamper, a method which contains detaching the stamper after transferring the concave-convex structure of the stamper, and thereafter curing the resin composition by irradiation of an activation energy ray, and the like.
Among these, with consideration for the transcription property of the nano concave-convex structure and the flexibility of the surface composition, the method which contains curing the resin composition by irradiation of an activation energy ray to transfer the nano concave-convex structure is suitable. This method is particularly suitable in the case of using a belt or roll stamper by which the continuous production can be conducted, and is an excellent method in productivity. However, in the case of this method, it is necessary to adjust the viscosity of the resin composition to transfer the nanosize concave-convex structure. Also, if the strength of the cured material of the resin composition is too high, it may be difficult to detach the stamper. Thus, since it is necessary to adjust the viscosity of the resin composition and the strength of the cured material, the usable resin composition is limited.
Also, the nano concave-convex structure body has an abrasion resistance inferior to that of a molded body such as a hard coat produced by using the same resin composition which has a flat surface, and there is a problem in durability during use.
Conventionally, a nano concave-convex structure body obtained by the method which contains curing the resin composition by irradiation of an activation energy ray to transfer the nano concave-convex structure and a resin composition for forming a nano concave-convex structure are proposed. Also, there is known a method for easily developing water-repellency by compounding a water-repellent component such as a fluorine compound or a silicone compound to a resin composition. In particular, a fluorine compound can be used to make the surface free energy extremely low. Further, a fluorine compound can develop an oil-repellency that cannot be developed in a silicone system.
For example, Patent document 1 discloses a cured coating with an excellent abrasion resistance and antifouling property by using a fluorine monomer component having a specific structure. Also, Patent document 2 discloses a curable composition containing a fluorine-containing polymer. Also, Patent document 3 discloses a polymer containing both silicon and fluorine which can give an antifouling property and a slipping property. Also, Patent document 4 discloses a post processing treatment by applying a fluorine compound on the surface of nano concave-convex structure body, and it is coupled by silane coupling reaction or the like.